Silk screen printing machine for decorating conical articles



July 21, 1970 I J, MOREL, ETAL 3,521,298

SILK SCREEN PRINTING MAcHINE FOR DECORATING CONICALQARTICLES Filed Nov. 21, 1967 4 Sheets-Sheet 1 Fly I A/Kqg $3 I: v

" \NVENTORSI IEHN MamdfRu Mlcun 37R. HU'BERT TBY WJ ATTORNEYS July 21, 1970 J. M. E. MOREL HAL Filed Nov. 21, 1967 4 Sheets-Sheet 2 Jam hr. 6. H0361 l l/cHgL 17 flL/ZEKT FT Nif/i I SILK SCREEN PRINTING MACHINE ROR DECORATING CONICAL ARTICLES Filed Nov. 21, 1967 July 21, 1970 J, MOREL ETTAL 4 SheetsSheet 5 IHVCENTO'RSI Ire-nu ME. MORE'L.

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g ATT RNEY- July 21, 1970 J, MOREL EI'AL 3,521,298

SILK SCREEN PRINTING MACHINE FOR DECORATING CONICAL ARTICLES 4 Sheets-Sheet 4 Filed Nov. 21, 1967 mvENToRj:

J'Em/ M. E. monec United States Patent Int. Cl. B41r 17/28 US. Cl. 101-40 3 Claims ABSTRACT OF THE DISCLOSURE An endless conveyer carrying spaced-apart work holders moves beneath a series of stationary screen printing stations. Articles in the work holders are axially rotatable, and the squeegees above the screens are reciprocable, in synchronism with movement of the conveyer. The conveyer is tiltable to make the tangential plane of the articles parallel to the screen.

The present invention relates to a machine for the serigraphic decoration of articles having an external surface of revolution, more particularly of articles having a substantially truncated conical external surface.

The process of serigraphic printing or silk-screen printing is very well known. In order to decorate the surface of an article of the aforesaid kind by this process, it is brought into rolling contact with a screen supporting or incorporating a stencil, the pigment or colour used for printing being spread across the screen by means of a squeegee which is applied to the line of contact between the article under treatment and the screen. Said screen may consist for example of a fine wire gauze all the meshes of which are blanked ofi with the exception of those within an outline corresponding to the decoration or design to be printed on the article; the pigment passing through these meshes reproduces this design and prints it on the surface of the article.

' In the case of polychrome printing of articles by passing them in succession beneath a plurality of screens charged with different pigments, it is essential that exact registration of the surface of the article presented to the screens at any instant should be reproducible during the difierent phases of the decoration operation in order to prevent any undesirable overlapping of the dilferent colours.

Various solutions have been proposed for this problem, among which there may be mentioned the use of photoelectric indexing cells and the employment of indexing projections forming an integral part of the articles to be decorated.

The present invention provides a much simpler solution of the problem.

According to the invention a machine is provided which enables complicated polychrome decoration to be carried out, the number of colours used being susceptible to modification very simply by the adding or omission of decorating stations, i.e. silk-screen printing stages, with- 3,521,298 Patented July 21, 1970 which conveys the articles at a uniform rate from a loading station where they are mounted on rotary work heads fixed to the machine, through a plurality of decorating stations to an unloading station.

According to another feature of the invention the conveyor belt and the work heads are mounted together upon a tiltable chassis, in such manner that when printing on articles of truncated conical shape, the chassis can be adjusted to a position such that the common tangential plane passing through all the upper generating surfaces of the articles placed on their supports will coincide with the working plane of the printing devices applied thereto.

According to another feature of the invention, the work heads for the articles are axially rotatable, the rotation being controllable by the movement of the belt, for example with the aid of pinions fast with the axles on which the work heads are mounted and engaging with a stationary rack located parallel to the belt in such a manner that the translatory movements of the belt and the axial rotation of the work heads produce exactly equal angular movements of the median zones of the articles to be decorated.

According to another feature of the invention, each decoration section comprises a horizontal screen fixed longitudinally and transversely and at least one squeegee which moves parallel to the belt, the position of each squeegee being controlled mechanically by a link motion derived from the displacement of the belt in such a manner that during the instant of each impression during which the pigment is forced by the squeegee through the meshes of the screeen, the vertical working plane of the squeegee coincides with the vertical plane through the axis of the work head carrying the article under treatment.

According to another feature of the invention the screen and each of the squeegees of each decorationsection are movable vertically with respect to a fixed chassis.

According to another feature of the invention, one and the same transmission chain provides for the movement of the endless belt, for the movements of each squeegee and for the control of the vertical movements of the squeegees and of the screens, and also for the force with which the squeegees are applied to their associated screens.

According to another feature of the invention, mechanical means are associated with each decoration section for the purpose of controlling as required the positions of the screen and of each of the squeegees both as to height and in the longiutdinal direction of movement of the conveyor belt and particularly for controlling the end vertical and horizontal travel of the squeegees and the end vertical travel of the screen.

In order more clearly to understand the invention, reference is made to the accompanying drawings, which illustrate diagrammatically and by way of example, a preferred embodiment of machine in accordance therewith and various details of the construction thereof.

In said drawings:

FIGS. 1, 2 and 3 depict an elevation, a plan view and a right hand end elevation respectively, of the complete machine according to the invention.

FIG. 4 represents a right hand end elevation of the machine with a vertical section in a vertical plane passing through the driving axle of the conveyor belt of the machine.

FIG. 5 is a vertical section of the machine in two transverse vertical planes passing respectively through the axis of one work head for the parts of the machine linked to its fixed foundation and through the driven axle of the conveyor belt of the machine for the parts of the machine associated with the mobile chassis.

FIG. 6 is a perspective and partially exploded view of the front portion of a decoration section which shows inter alia the control of the movement of the squeegees and the control of the actuation of the pneumatic jacks.

FIGS. 1, 2 and 3 will enable the general principle of operation of the machine according to the invention to be well understood.

The machine comprises a fixed base 1, on which are mounted in line, a series of decoration sections 2a- 2n. A mobile chassis 3 extends longitudinally for the whole length of the base 1 and is articulated thereto about a horizontal axis of articulation 4. A plurality of control members 5 (of the type of levelling screws) enables the angle of tilt of the chassis 3 to be controlled about the axis 4 in relation to the base 1.

The tiltable chassis 3 comprises an endless conveyor belt 6 on which are mounted a certain number of work heads 7, which are uniformly spaced apart horizontally, each work head being adapted to receive an article A to be decorated for example a bottle or a goblet or tumbler particularly of truncated conical shape, and which is adapted to rotate it about its axis 7a parallel to the base 1 of the chassis 3 and adjustable therewith. The rotation of articles about the axes 7a of the various work heads 7, is synchronised with the forward feed movement of the belt in a manner which will be explained more fully in the following.

Each one of the decoration sections 2a, 221-1211 which are integral with the fixed base of the machine comprises a screen (8a, 8n and a squeegee (9a, 9n The screen in each decoration section can be displaced vertically, but its plane always remains horizontal. In the same way each squeegee can be displaced vertically, its working edge always remaining parallel to the screen and perpendicular to the longitudinal axis of the machine, that is to say, to the axis of displacement of the articles A. Moreover, the initial positions of the screen and of the squeegee are individually and separately controllable for each decoration section.

Owing to the variable tilt of the chassis 3, whatever may be the taper of the articles A (varying for example from to 10) it is always possible by operating the devices to bring the chassis 3 into a position such that the common tangential plane passing through all the upper generating surfaces S of the articles A present at any moment on the upper side of the belt 6, is a horizontal plane parallel to the fixed screens 8a, 811 This constitutes an important feature of the invention because it enables decoration to be carried out with the same screens (obviously after suitably regulating the working height of the screens and of the squeegee) on articles of different geometrical shapes and especially of different taper.

The synchronisation of the linear movement of the belt and of the axial rotation of the work heads 7 is effected in such manner that the articles A located below the screens in the manner shown are in rolling contact therewith. As will be seen more clearly in the following, such a relative movement is achieved by mechanical control.

The squeegee in each decoration section is actuated by a longitudinal reciprocating working stroke combined with vertical movements which bring it either into the working postion (squeegee applied to the screen and forcing pigment between the meshes) or in the retracted position (slight lifting of the squeegee and also of the screen). The reciprocatory movement of the squeegee is also linked to, and controlled mechanically by the linear movement of the belt 6 in such manner that the squeegee in its working position is in a vertical plane passing through the axis of the work head carrying the article, thus ensuring printing thereon.

The overall functioning of the machine according to the invention is as follows:

The articles A are placed in a loading station 10 on the Work heads at the same rate at which these latter appear at the beginning of the upper flight of the belt 6. The belt 6 carries the articles along with the upper generating surfaces thereof being kept parallel to the screens, through the different decorating sections 2a, 21 the articles being in rolling contact meanwhile with the undersides of the screens. Each screen is charged with a different pigment and serves for the printing of a decoration in a specific colour. Owing to the fact that link motions are provided between the linear motion of the belt, the axial rotation of the articles and the position and movement of the Squeegees, there is no need whatever for any system of register since once initial register has been effected, the printing of decorations in different colours on the surface of the articles is carried out in a very exact manner so that the decoration produced by one section or one decocrating member is always applied in the same way and at the same point in the movement of the belt to the following article to be decorated.

Such a machine offers considerable flexibility of operation with respect to the number of colours utilised, owing to the fact that use can be made of each section, either independently or in combination. Thus for example, with a machine having four decorating sections a mode of operation can be arrived at which is analogous to that of:

-four machines with one screen one machine with one screen and one machine with three screens two machines with two screens one machine with four screens.

The general principles of the functioning of the machine having been described the mechanical principles used will now be set forth in greater detail.

BELT AND MOVEMENT THEREOF The belt 6 has two parallel flights and is mounted on the chassis 3 by means of two pairs of chain wheels 12a, 12b and 13a, 13b linked respectively to a driving shaft 14 and a driven shaft 15, these shafts being mounted on the tiltable chassis 3 by means of bearings 14a and 15a respectively. The belt is thus an endless belt the two parallel flights of which are interconnected by means of ties 16 located transversely thereto and acting as supports for the work heads 7. In its endless movement, the belt 6 is guided around the chassis 3 with the aid of vertical guide rollers 17 and horizontal guide rollers 18 co-operating with guide-ways 19 and 20 respectively.

The belt 6 is driven by means of a motor 21 through the intermediary of the following power transmission chain: motor 21, speed regulator 22, coupling 23, gearbox 24, coupling 24a, speed reducer 25, muff coupling 25a, bevel gear 26, faceplate coupling 27, driving shaft 14.

By virtue of this assembly, power transmission is effected from the motor which is mounted on the fixed base 1 of the machine, to a belt mounted on the tiltable chassis 3.

CONSTRUCTION AND MOUNTING OF THE WORK HEADS As the construction of such a work head does not form an essential part of the invention it will be only briefly described in conjunction with the construction of the machine. Each working head comprises a cap 30 mounted on a support 31 which is in turn, controllably and slidably mounted on a cross member 16 of the belt. Each cap 30 can be tilted between a position of loading/ unloading (shown in full lines in FIG. 5) and a working position (shown in dotted lines). Each work head moreover comprises a faceplate 32 integral with a shaft 33, and mounted with the aid of two bearings 34 on a bracket 35 mounted on the belt cross member 16. The articles (truncated conical goblets for example) are mounted in the following manner: the machine operator places them on the caps 30 erected in the loading position, this is sufficient to ensure that they are secure. The caps with the articles are then tilted into the working position (for which purpose the common upper tangential plane of the articles is horizontal) and with the cO-operation of a longitudinal ramp 36 (shown in section in FIG. for the purpose of clarity although they are in fact behind the plane of the drawing) with support rollers 37, the caps 30 and the articles are fed forward until contact is made with the faceplate 32 with a pressure sufficient to ensure the articles can be carried round by the rotation of the faceplate, that is to say, by the rotation of the shaft 33. The shaft 33 is rotated by means of a pinion 38 engaging with a longitudinal rack 39 which is co-extensive with the chassis 3. This pinion 38 preferentially has a diameter equal to the mean diameter of the curved surface of the article to be decorated.

In this way, rolling contact of the articles beneath the screens is achieved in an exact manner by means of a mechanical control (link motion).

DETAILS OF A DECORATION SECTION Each one of the decoration sections is mounted on a chassis integral with the base 1 of the machine. This chassis comprises vertical traversing members 40, longitudinal traversing members 41, transverse flanges 42 and horizontal supporting plates '43. Two vertical guide columns 44 and 45 are mounted oneach side of each decoration section. The columns 44 are for the purpose of guiding a screen carrier 46, the position of which is controlled by means of a jack 47 preferably of the pneumatic type, mounted on the plate 43. The guide columns 45 arefor the purpose of guiding vertically a squeegee carrier 48, the position of which is controlled by a jack 49 preferably of pneumatic type and likewise mounted on the plate 43. Associated with the member 48 are two superimposed longitudinal slide rods 48a and 48b, upon which a squeegee holder 50 can slide longitudinally.

Between the two flanges 42 of each decorationsection there are likewise mounted four longitudinal slide rods 51a, 51b, 52a, 52b. The slide rods 51a and 51b carry a slider member which imparts to the squeegee a movement which it receives in synchronization with the movement of the belt. The member with the reference 53 will in the following be termed an auxiliary member.

A member 54 which operates the squeegees, is mounted on the slide rods 52a and 52b. This driving member 54 is connected to the auxiliary member 53 by means of two link rods 55 of variable length. Finally, the driving member 54 is connected to the squeegee holder 50 by means of a slide 56, which permits vertical movement.

It will therefore be seen:

That the position of the screen connected to the traverser 46 is determined by the position of the jack 47,

That the height of the squeegee is determined by that of the traverser 48, and consequently by the position of the jack 49,

That the longitudinal position of the squeegee is determined on the one hand by the position of the auxiliary member 53 movable on its guide rods 51a, 51b and on the other hand by the length of the connecting rods 55 which control the longitudinal displacements of the driving member 54 in relation to those of the auxiliary member 53.

Under these conditions, once the preliminary control of the longitudinal position of the squeegee and of the travel of the jack has been dealt with, in order to bring about the mechanical control above described between the longitudinal travel of the belt and the positioning and motion of the squeegee there remains the question of convenient control of the movements of longitudinal displacement of the auxiliary member 53 in relation to the forward feed of the belt, while actuating the jacks 49 and 47, at suitable moments in the operating cycle. The solution adopted for this problem will be described in the following:

6 MECHANICAL CONTROL BY LINK MOTION From the gear box 24 there extends a train of shafting 60 comprising a series of link members 60a transmitting the same angular rotation to a bevel reduction gear 61 feeding each decoration section. The motion is transmitted in each decoration section to a bevel reduction gear 62 mounted upon a fixed support 63 through the intermediary of a clutch plate 64. Two longitudinal shafts 65 and 66 are taken from the speed reducer 62 and they drive a cam drum 67 having a cam groove 67a and a pallet drum 68 respectively.

The rotation of the pallet drum 68 sets in motion a pneumatically or electrically driven member 69 controlling the jacks 47 and 49. On the other hand, the rotation of the cam drum 67 brings about the movement of a carriage member 71 through the action of a follower roller 70 engaging in the groove 67a, said carriage being adapted to slide on two longitudinal slide rods 72. One revolution of the cam 67 corresponds to One reciprocatory movement of the carriage 71.

The' transmission of the reciprocatory movement of carriage 71 to the auxiliary member 53 is effected very simply (see FIGS. 5 and 6) with the aid of a mechanical amplifying lever 73 pivoted on an axle 74 mounted on the fixed traverse members 41, one end 73a of said lever cooperating with the auxiliary member 53 and the other end 73b cooperating with the carriage 71.

By this means the control of movement of the squeegee is linked in a very simple way to the forward movement of the conveyor belt as is also the case with the control of the lowering and raising of the screen and of the squeegees.

It is Obviously convenient to execute the following control movements each time the article to be decorated is changed:

Controlling the tilt of the chassis depending on the taper of the articles,

Controlling the working distance between the cap and back plate of each work head, for example by transverse movement of the ramp cooperating with the rollers of the tiltable caps,

Changing the driving pinion of each work head cooperating with the rack,

Changing the working level of the screen in relation to the conveyor belt,

Controlling the position of the screen both longitudinally and transversely,

Controlling the force of application of the squeegee on the screen (travel of the jack 49),

Controlling the height of the squeegee.

All these control movements can be achieved in the machine according to the invention and especially by virtue of the vertical guide columns and horizontal slide rods.

Attention is drawn to the special advantages of the machine according to the invention as compared With existing machines, due essentially to the fact that all the control movements are interdependent and apart from the reciprocation of each carriage and of the members associated with each decoration section they are continuous as to direction and speed. In addition to the advantage of a simple mechanical ensemble, inertia effects due to changes in speed and direction are eliminated, while any play is always taken up in the same direction and finally the machine is available, all of which enables high rates of production to be attained even with relatively low linear speeds of the conveyor belt.

The advantages arising from the abolition of register devices either on the articles to be treated or on the machine, have already been explained.

It will be understood that the present invention is not limited to the precise mode of performance described but includes all the variations in accordance with the spirit and scope thereof. In particular the maintenance in a common vertical plane of each squeegee and of the axis of the work head of the article above which the squeegee operates during its printing stroke and which in the embodiment described is carried out by a link motion, could equally well be effected by making the squeegee temporarily integral with the conveyor belt when the latter passes the Work head. In'the same way one decoration section could comprise a plurality of squeegees or of squeegee elements. 1

We claim:

1. A silk screen printing machine for decorating conical articles, said machine comprising a loading station, a plurality of printing stations each having serigraphic screen means and squeegee means, an unloading station, a continuously moving conveyor for carrying the articles from said loading station through said printing stations to said unloading station, said conveyor including work holders for the articles rotatable about axes transverse to the direction of movement of said conveyor, means for continuously rotating each of said work holders in synchronism with the movement of said conveyor as each work holder moves from said loading station to said unloading station, said serigraphic screen means being fixed along'the path of said conveyor, and said squeegee means being displaceable in synchronism with and parallel to said conveyor, whereby an article carried by any of said work holders is presented to each printing station in a predetermined angular orientation with respect to the axis of rotation of its work holder and is decorated at each station in synchronism with the movement of said conveyor, a chassis upon which said conveyor is mounted, and means for tilting said chassis about an axis parallel to the direction of travel of said conveyor so as to adjust the orientation of a plane tangent to 'all the articles, whereby said plane can be made parallel to said screen means and articles having dilferent conical angles may be decorated.

2. A silk screen printing machine as defined in claim 1, including a motor for actuating said conveyor, transand bevel gears for transmitting motion from said transmission means to said cams.

3. A silk screen printing machine as defined in claim 1 in which said conveyor comprises two endless chains and a series of parallel cross members connecting said chains, and each of said work holders comprises a face plate and a tiltable cap, said plate and cap being mounted on one of said cross members and being relatively movable toward and away from each other.

References Cited UNITED STATES PATENTS 2,066,351 1/1937 Johnson et al. 118-230 2,121,491 6/1938 Soubier 101-123 2,975,705 3/ 1961 Gilman 101-123 3,195,451 7/1965 Hovekamp et al. 101-38 3,263,603 8/1966 Fuchs 101-123 2,132,818 10/1938 Cone 101-123 XR 2,183,223 12/1939 Mankin et al 101-124 2,198,565 4/1940 Schutz et al 10l-40 XR 2,739,531 3/1956 Hagerman 101-126 2,757,606 8/ 1956 Dubuit 101-126 2,920,556 1/1960 Medert et al. 101-38 3,113,510 12/1963 Dubuit 101-124 3,172,357 3/1965 Rudolph et al. 101-126 3,253,538 5/1966 Rudolph et al. 101-126 XR 3,273,618 9/1966 Flodin 198-19 XR ROBERT E. PULFREY, Primary Examiner C. D. CROWDER, Assistant Examiner U.S. Cl. X.R. 

